Groundwater flow in a small watershed in a hard rock region of Andhra Pradesh, India mainly exists in a coupled system of weathered and fractured rock aquifers. However, due to heavy extraction, groundwater level has declined and the weathered part has become unsaturated. In general, the water-table aquifer exists in the area under semi-confined or unconfined conditions. Monthly water-levels fr...

We explore the contribution of fractures (joints) in controlling the rate of weathering advance for a low-porosity rock by using methods of homogenization to create averaged weathering equations. The rate of advance of the weathering front can be expressed as the same rate observed in non-fractured media (or in an individual block) divided by the volume fraction of nonfractured blocks in the fr...

Groundwater flow in sedimentary rock saprolite, and in soils derived from this material, is strongly influenced by sedimentary layering and fractures inherited from the parent bedrock. The main objectives of this study were to determine whether parent bedrock lithology and infilling of fractures and other macropores with pedogenically derived clays and Fe/Mn oxides also play major roles in cont...

Weathering pro®les developed on organic carbon-rich black shales were studied to examine the loss and degradation of organic matter (OM) during weathering and its role in the geochemical carbon cycle. Analysis of weathered shales reveals between 60 and nearly 100% total organic carbon (TOC) loss in highly weathered samples relative to initial, unweathered TOC content. Pyrite loss coincides with...

The hydrodynamic properties of the weathered-fractured layer of a hard-rock pilot watershed in a granitic terrain are characterized using hydraulic tests at different scales. The interpretation of numerous slug tests leads to characterize the statistical distribution of local permeabilities in the wells. The application of flowmeter profiles during injection tests determines the vertical distri...

Isotopic signatures are used to distinguish Group I, Transition, and Group II kimberlites, and provide information on the origin of melts parental to the final intrusion. Kimberlitic rocks are often weathered and altered, making them potentially unsuitable for whole rock isotopic studies. We therefore have explored the alternative use of the isotopic signatures of resistant minerals in kimberli...